I am almost done with my Windows based front end. Doesn't help you for a DOS cab though. Right now it's set to run at 800x600 but I'm working on making it either resizable or available in a couple of different resolutions.
The goal of my front end is to be the simplest front end to set up. Most of the configuration options on mine are completely optional. If you want to change the background picture, font colors, add details and screenshots, great! If you don't want to, it still works. The other thing I've done is made it user-friendly for all emulators, not just MAME.
I've actually made a couple of different "skins" (they're really just INI files that allow you to change the program's colors and background graphics) to show some of the program's versitility.